Modems are currently utilized as discrete computer peripherals that interface a host device such as a personal computer (PC), with an external broadband gateway or access network such as provided by a cable television or telecom company. A modem may be considered a “front-end” device, which retrieves information from the access network and provides the information to a “back-end” device, such as a PC. In a typical configuration, a modem such as a digital subscriber line (DSL) or cable modem interfaces to a PC via a peripheral component interconnect (PCI) slot associated with the PC.
The PCI slot is typically one of many PCI slots or interface connections sharing a common PCI bus architecture. Thus, access of one device communicating via the PCI bus results in at least a brief servicing of a PCI bus interrupt or other command by each of the other devices communicating via the PCI bus. This brief servicing requirement tends to produce “jitter” or other timing anomalies, which may be deleterious to the routing of time sensitive data.
In the case of MPEG audiovisual data, excessive network jitter, or the improper recovery of the 27 MHz clock associated with an MPEG transport stream can cause buffer overflow, buffer underflow, undesirable color changes and other deleterious phenomenon which result in improper presentation of the audiovisual material being conveyed. Such network jitter or improper clock recovery (or other timing operations) may be caused by PCI bus access/servicing.